some people in sloan told me NYU are very hard to get in. If you want to apply Kellog, u'd better have good score on real analysis. I just learned from its website. Besides, what are the maths courses u have taken?
I think your maths is good enough for a top 50 finance program. However, I am not sure whether good enough for top 20. However, since you are in US, you stand a good position.